1. Field of the Invention
The present invention is directed to a method for preparing a temporary aqueous aerosol paint composition. In particular, the aqueous aerosol paint composition of the present invention may be utilized in temporary marking applications such as, for example, marking the location of underground utility lines, as is common in the construction industry.
2. Description of the Related Art
Aerosol paints are utilized in a variety of applications, including those typically associated with standard (i.e., non-aerosol) oil or water based paints. This is a result of the numerous advantages of an aerosol delivery system. For example, the application of an aerosol paint often requires less skill than is typically required to properly apply a standard oil or water based paint. In addition, the use of an aerosol paint eliminates the need for cleaning paint brushes, paint rollers, paint trays, etc., as is required after the application of standard paints. Also, in certain instances, aerosol paint may be readily applied to surfaces which may be awkward and/or difficult to access, thereby hindering the application of standard paints.
Due to the numerous advantages of aerosol paints, their use has become widespread for both home and commercial applications. One particular area of widespread commercial usage of aerosol paints is in the construction industry, and in particular, the non-permanent identification of various structures and/or materials on or around a construction site, for example, site boundaries and/or locations specified by a surveyor, identification of the location of underground utility lines and/or other underground structures, identification of building materials, etc.
Historically, the aerosol paints utilized in the construction industry and, in fact, aerosol paints in general, comprise a mixture of volatile organic solvents, as well as, typically, an equally volatile aerosol propellant. While this combination of volatile compounds results in a stable and usable aerosol paint composition, the hazardous aspects of such volatile compounds are now all too well known. To begin, such compositions are typically flammable, due to the concentration of highly volatile compounds, and as such, these compositions are dangerous to store, transport, and handle, and the potential of a fire, or worse, an explosion, due to mishandling is a constant concern. In addition, it is also now well documented that exposure to such volatile organic compounds, even in limited amounts, presents a health hazard to the persons who are exposed to them. This exposure hazard exists for persons who are directly applying such volatile compositions as well as those who may simply be present in the general vicinity in which they are being applied. Aside from the potential fire, explosion, and health hazards presented by such volatile aerosol paint compositions, such compositions are also believed to be a factor in the further depletion of the ozone layer and thus, they are believed to contribute to the phenomenon now commonly known as “global warming,” which, if left uncontrolled, is believed to pose a potentially devastating threat to the very existence of our planet.
Attempts to address the negative aspects of such volatile aerosol paint compositions, as outlined above, have resulted in the development of formulations which reduce and/or eliminate the reliance on volatile compounds in aerosol paint compositions, with varying degrees of success. For instance, although a number of aerosol paint compositions have been formulated which no longer require a volatile organic solvent, many of these formulations still utilize a volatile organic propellant, thereby still presenting the hazards presented above, albeit to a somewhat lesser degree. In addition, these formulations are reportedly prone to foaming problems upon application, due to entrapment of the volatile organic propellant in the non-volatile paint component. Also, many of these formulations are known to be unstable even after only a short period of time.
Further attempts to improve aerosol paint formulations include the use of essentially non-volatile compounds in both the paint component and the propellant component, however, many of these formulations still reportedly exhibit excessive foaming so as to limit their widespread commercial usage. In addition, these later formulations still typically contain other harmful organic compounds and, as such, they continue to present a health hazard to persons who directly apply them or are otherwise exposed to them.
In addition, the currently known and purportedly “temporary” aerosol marking paints utilized in the construction industry today are formulated such that they typically remain visible from between several months to and more than a year after application, depending upon the type of surface or material on which they are applied, and the climatic conditions in the region of application. Aside from the obvious eyesore such lingering markings present, a more serious issue is the safety hazard created due to potential confusion in determining exactly what the various and often overlapping markings are supposed to indicate. As should be appreciated, the potential of a construction crew digging or drilling in an area where underground gas, electric, water, and/or sewer lines are not clearly identified presents a serious risk to the health and well being of the crew, as well as the persons in the immediate and surrounding areas.
As such, it would be beneficial to provide an aerosol paint composition which minimizes and/or eliminates the negative attributes identified above, yet is formulated for ease of handling and consistency of application. More in particular, such an aerosol paint composition would preferably comprise an aqueous paint component, including an aqueous solvent, as well as an aqueous propellant component. It would be further beneficial for such an aqueous aerosol paint composition to comprise compounds which minimize and/or eliminate the hazards presented to users and the environment relative to the various volatile and non-volatile organic compounds typically included in aerosol paint compositions, as discussed above. Preferably, any such aqueous aerosol paint composition would be formulated to provide a highly visible marking in a variety of fluorescent colors such that various structures and/or materials on or around a construction site may be clearly marked so as to eliminate confusion. Yet another benefit would be for such an aqueous aerosol paint composition to naturally and essentially completely degrade within weeks rather than months of application. A further advantage would be achieved by providing a simple and cost effective method for preparing and packaging such a temporary aqueous aerosol paint composition to permit widespread usage within the construction industry and elsewhere.